Side-loading fork lift vehicles (sometimes also referred to as "fork lift trucks") have been well known for many years. See, for example, Hegarty U.S. Pat. No. 2,591,544; Lull U.S. Pat. No. 2,621,811; Erickson et al. U.S. Pat. No. 3,031,091; Quayle U.S. Pat. No. 3,167,201; Jinks et al. U.S. Pat. No. 3,168,956, and numerous others. Such vehicles lend themselves readily to handling loads which are stored or to be stored in multi-level stacks or racks separated by narrow aisles and having relatively restricted vertical clearance between levels, and by virtue of their structural and operating characteristics enable more of the available ground space of the storage facility to be profitably occupied by the stored loads and less of the ground space to be wasted in unoccupied wide aisles between the stacks or racks.
Such an optimization of storage space vs. aisle space utilization is especially important in an automotive junk yard because of the fact that junked or wrecked cars, which have to be stored in multi-level racks, are not only long relative to their width but are also exceedingly bulky. Prior to the invention described and claimed in the aforesaid application Ser. No. 342,999, however, the operation of such automotive junk yards had been a rather uneconomical undertaking because of the need to leave large aisles between adjacent racks to accommodate the relatively great maneuvering room required by the conventionally used front-loading fork lift trucks for removing cars from or placing them into the racks. Thus, the number of cars that could be stored in any given facility was likewise limited, which, with land values and labor costs continuously on the rise, put a severe strain on the profitability of the storage facility.
The side-loading fork lift trucks known prior to the development of the vehicle according to the invention described and claimed in application Ser. No. 342,999, as far as the present inventors are aware, had not been used in the storage of junked or wrecked cars and had not been suited for such use, even when designed for lifting relatively long loads such as pipes and timbers. In particular, such side-loading fork lift trucks have a very limited capability in terms of the height to which they can elevate a load, usually not more than about 12 feet (3.66 meters) off the ground. Moreover, as the above-cited representative patents make clear, in the known side-loading fork lift trucks the problems being dealt with have generally been one or another of the individual problems of counter-balancing the load, vehicle stability, load distribution between the wheels of the vehicle, or the like. Also, the known side-loading fork lift vehicles have generally been relatively short, and thus maneuverability problems have not arisen in connection therewith or been insuperable. However, it appears that none of the prior art patents has ever dealt with the totality of the vehicle operation.